A conservation plan for Atlantic salmon (Salmo salar) and anadromous brown trout (Salmo trutta) in a region with intensive industrial use of aquatic habitats, the Hardangerfjord, western Norway

Figures & data

Figure 1. Map of the Hardangerfjord basin, with location of rivers with Atlantic salmon and anadromous brown trout.

Table I. The 12 largest rivers with Atlantic salmon and anadromous trout in the Hardangerfjord, showing length of river available for anadromous fish, extent of water regulation (No; +: some; ++: extensive), level of impact on populations of salmon (S) and anadromous trout (T), and major category of impact. L: salmon lice; W: water quality; R: hydropower generation.

River	Length (km)	Regulated	Affected populations	Factor
Etneelva	12.2	+	S +T: moderately	L
Uskedalselva	10.3	No	T: moderately	W
Granvinelva	7.5	+	S+T: highly	L
Eidfjordvassdraget	6.6	++	S: highly; T: moderately	R
Opo	1.5+	No	S: highly; T: moderately	L
Æneselva	5.7	No	T: highly	L
Steinsdalselva	5.0	No	S+T: highly	L
Rosendalselva	5.0	+	S+T: highly	L,R
Ådlandselva	4.6	No	T: moderately	L
Omvikedalselva	4.4	No	T: moderately	L
Sima	4.3	++	T: highly	R
Kinso	4.2	No	S: highly; T: moderately	L

Figure 2. Atlantic salmon catch statistics for the River Etneelva, and River Eio and River Bjoreio in Eidfjord, the major river systems in the Hardangerfjord basin (Statistics Norway 2010).

Figure 3. Diagram showing movement of unfertilized eggs and milt between salmon river and the gene bank, movement of eyed eggs from gene bank to local fish station and salmon river, and movement of fry and parr from local fish station to salmon river.

Table II. Number of family groups and brood fish from Hardangerfjord rivers in the living genebank.

River	No. of family groups	No. of individually marked fish	No. of group-marked fish
Eidfjordvassdraget	56	523	2500
Etneelva	33	0	5000
Total	89	523	7500

Table III. Number of milt samples collected from Atlantic salmon in Hardangerfjord rivers from 1986 to 1999.

	Year
River	86	87	88	89	90	91	92	93	94	95	96	98	99	sum	wild
Eidfjordvassdraget		2	7	2	9				8	6	3	2	3	39	35
Etneelva	16	12	3	7	12									50	45
Granvinselva				10	7	12	5	6	10		2			52	35
Jondalselva				7	8	7								22	13
Omvikedalselva				7	4									11	8
Opo			8	10		3	5		4	4	4	2		40	24
Rosendalselva				2	3	4	1	4						14	6
Guddalselva						1	1							2	2
Steinsdalselva						3	1	6	2					12	8
Uskedalselva				3	5	2	3		5					18	13
Øysteseelva				10	11	8	6							35	23
Total	16	14	18	58	59	40	22	16	29	10	9	4	3	295	212

Figure 4a. Generalized schematic of resistance board weir installed in a gravel bed stream. A, Rigid weir; B, Fish way; C, Picket weir panels; D, Bulkhead; E, Resistance board; F, Substrate rail and anchor; G, Live trap location; Inset: b, Tension harness; c, PVC pickets; e, Resistance board. Flow pressure against board causes lift of weir panels.

Figure 4b. Photo of complete trap in Williamson River, Oregon (Photographer: J. Anderson).